Immer Integration

Learn how Immer enables immutable updates with mutable syntax in Redux Toolkit.

20 min

2 sections

immer

immutability

state-updates

01. Why Immer?

Section 1 of 2

Redux requires immutable state updates, but writing immutable code can be verbose. Immer lets you write code that looks mutable while maintaining immutability under the hood.

typescript

// Traditional immutable update (verbose)
return {
  ...state,
  todos: [
    ...state.todos.slice(0, index),
    { ...state.todos[index], completed: true },
    ...state.todos.slice(index + 1)
  ]
};

// With Immer (clean!)
state.todos[index].completed = true;
return state;

Exercise

Update State with Immer

Practice

Write a reducer that updates a nested property using Immer's mutable syntax.

createSlice API

Action Creators & Payload

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